A conventional double-layer container discloses a double-layer container with an inner layer on which decoration plates are attached and the decoration plates are located at distances. The conventional double-layer container includes at least one slot defined through the outer layer and the at least one slot is filled by a filling which forms a 3-D pattern protruding from the surface of the outer layer. The conventional method is able to make a double-layer container that includes spiral decoration plates or sections of decoration plates.
However the spiral decoration plates or sections of decoration plates are on the inner layer of the container, which means that dirt or foreign objects are easily accumulated at the connection portions between the inner layer and the decoration plates and fungus is found at the connection portions.
U.S. Pat. No. 6,763,962 discloses a container with double layers and is shown in FIGS. 7 and 8, wherein the container includes an inner layer C which includes a portion protruding from the surface of an outer layer B via a hole B1 in the outer layer B, such that the portion seals the hole B1 and covers the periphery of the hole B1. By this way, the inner layer C and the outer layer B are combined to each other and the inner and outer layers are not separated from each other by impact.
As shown in FIG. 7, the prior art discloses the hole B1 defined through the outer layer B and the inner layer C is poured between an outer mold member D and an inner mold E. The outer mold member D has a cavity D1 corresponding to the hole B1 of the outer layer B and a 3-D pattern C1 is formed in the cavity D1. The 3-D pattern C1 extends outward from the hole B1 to seal and cover the hole B1. The profile of the 3-D pattern C1 is the same as the shape of the inner surface of the cavity D1 so that the 3-D pattern C1 protrudes out from the surface of the outer layer B.
However, as shown in FIG. 8, the 3-D pattern C1 is connected to the outer surface of the outer layer by a connection portion C2 which is easily broken when a vertical force or load is applied to the outer layer B. Besides, the outer layer B includes a smooth surface and the multiple 3-D patterns C1 are individually disposed on the outer layer and cannot perform desired aesthetic profile.
U.S. Pat. No. 6,264,132 discloses a box-like container with an interpenetrating structure and process for realization thereof, wherein the container includes an integral outer layer with notches or holes and plastic material is poured to form an inner layer which includes portions having a thickness that is located corresponding to the notches or the holes so as to fill the notches and the holes to form a smooth surface on the outer layer. The notches or the holes and the portions include tapered surfaces so as to firmly connect the inner layer to the outer layer, such that the inner layer does not separate from the outer layer by forces applied to the container.
The applicant invented the prior art and combines different materials and/or colors to the container so as to produce a unique container that is different from the conventional containers in appearance. The portions that fill the holes or notches are smooth and flush with the outer surface of the outer layer so that the portions are not separated from the container. However, the thickness of the portions of the prior art is substantially identical to the thickness of the sum of the thickness of the inner and outer layers such that the container lacks 3-D patterns.